Recent popularization of wine is nothing short of eye opening, and brands, producing areas, kinds, tastes, and the like of the wine are diversified with the popularization of wine. This trend, for example, promotes opening business of a bar specializing in wine, which is so-called a wine bar, and a large variety of wines corresponding to customers' tastes have been offered at such a wine bar. This type of the wine bar, for example, offers a small amount of free samples among various brands of wines in order for customers to choose a wine of their tastes among the large variety of wines, or sells the wine by weight to the customers who want to purchase the wine in a glass unit, and therefore, many bottles need to be opened at the same time. However, since air enters the bottle once opened, deterioration of wine is inevitable when there is leftover wine in the bottle even though this problem does not happen when wine is drunk up. When leftover wine after opening the bottle deteriorates to a certain extent after a certain amount of time passes, there is no other choice but to throw leftover wine out. This is a waste of wine.
As a means for avoiding such an inconvenience, a liquid preserving device having a structure described below has been proposed (Japanese Patent Laid-open No. 2001-354206). This device has such a purpose that air in the bottle is inhaled by a vacuum pump through a pressure-reducing stopper installed on an opening of the bottle so that the deterioration of wine remaining in the bottle can be prevented.
In addition, an applicant of the present invention previously proposed a wine extracting device having such a structure that the device is mounted on an opening of the bottle, and that the bottle is opened while supplying insoluble inert gas with the opening of the bottle positioned downward, and consequently only a necessary amount of wine is extractable by gas pressure thereof (Japanese Patent Laid-open No. 2001-122397).
However, according to the aforementioned liquid preserving device, an existing bottle stopper must be opened in air in order to install the pressure-reducing stopper as a substitute stopper. Accordingly, air enters the bottle when opening the bottle stopper. Consequently, oxidation of the remaining wine by the entered air, that is, deterioration in a quality of wine, is inevitable.
Furthermore, the aforementioned wine-extracting device relating to the proposal of the applicant of the present invention is a device for extracting wine from the bottle without oxidizing wine by using insoluble inert gas, and not a device for changing the bottle stopper with the substitute stopper like the pressure-reducing stopper.
An object of the present invention is to provide a device for changing a bottle stopper and a method for changing a bottle stopper capable of changing the existing bottle stopper with the substitute stopper without allowing air to enter the bottle with fluid contained therein. In passing, the fluid includes not only liquid such as wine, carbonated water, and so on, but also overall fluid such as lactic acid bacteria beverage, fruit juice with pulp, fluid having a large fluid resistance such as edible oil, and so on.